Viennella ignorata, Harzhauser & Landau, 2019

Harzhauser, Mathias & Landau, Bernard, 2019, Turritellidae (Gastropoda) of the Miocene Paratethys Sea with considerations about turritellid genera, Zootaxa 4681 (1), pp. 1-136 : 79-81

Viennella ignorata new sp.

Figs 6 Ag, 21E, 21F, 21G, 21H, 21I

Turritella (Haustator) laevissima subrotundula Sacco — Sieber, 1960: 242, pl. 1, figs 17, 31 [non Turritella laevissima Mayer, 1866 , non Turritella (Haustator) laevissimus subrotundula Sacco, 1895 ].

Turritella sp. — Strausz, 1966: 102, pl. 3, fig. 21.

Haustator Miohaustator [sic] laevissimus Mayer — Stürmer, 1989: 125, pl. 4, figs 6, 8, 9, pl. 12, figs 4, 9 [non Turritella laevissima Mayer, 1866 ].

Turritella (Haustator) laevissima subrotundula Sacco — Schultz, 1998: 56, pl. 21, fig. 6 [non Turritella laevissima Mayer, 1866 , non Turritella (Haustator) laevissimus subrotundula Sacco, 1895 ].

Types. Holotype NHMW 1963/0528/0000 ( Fig. 21F ), SL: 25.7 mm, MD: 7.5 mm, Steinebrunn ( Austria), illustrated in Sieber 1960, pl. 1, fig. 17) as Turritella (Haustator) laevissima subrotundula Sacco . Paratypes NHMW 2018/0303/0003 ( Fig. 21E ), SL: 29.8 mm, MD: 9.3 mm, Bad Vöslau ( Austria) ; NHMW 2018/0272/0005 ( Fig. 21G ), SL: 21.3 mm, MD: 6.2 mm, Gainfarn ( Austria); NHMW 1963/0551/0000 ( Fig. 21H ), SL: 23.8 mm, MD: 6.7 mm, Steinebrunn ( Austria), illustrated in Sieber (1960, pl. 1, fig. 31) as Turritella (Haustator) laevissima subrotundula Sacco ; NHMW 1871/0010/0379 ( Fig. 20I ), SL. 18.1mm, MD: 6.2 mm, Steinebrunn ( Austria) . Additional paratypes. 8 spec. NHMW 2010/0004/0449, 1. spec. NHMW 2018/0303/0004, 13. spec. NHMW 2018/0303/0005, Bad Vöslau ( Austria) ; 1 spec. NHMW 1963/0528/0000, 1 spec. NHMW 1963/0551/0000, 7 spec, NHMW 1871/0010/0379, Steinebrunn ( Austria) ; 1spec. NHMW 2018/0272/0006, Gainfarn ( Austria) .

Type stratum. Marly clay (‘Tegel’) of the Baden Group.

Type locality. Baden ( Austria).

Age. Middle Miocene, Badenian (= late Langhian).

Etymology. Referring to the fact that this species was ignored in previous studies on Paratethyan Turritellidae .

Description. Shell small, moderately slender, of c. 15 teleoconch whorls. Protoconch and early teleoconch unknown. Earliest preserved teleoconch whorls only weakly convex with periphery close above abapical suture, bearing six to eight broad, low spiral cords with slightly narrower interspaces. Later teleoconch whorls moderately convex or faintly angulated in abapical third of whorl, nearly flat sided above mid-whorl. Whorl profile flat sided to weakly convex or even slightly imbricate. Sculpture comprising about 8 to 10 spiral cords being most prominent along periphery. One weaker secondary spiral cord may be intercalated between primaries in adapical half of whorls and is always present between primaries in abapical half of whorl. Tertiary spiral threads may be intercalated as well, resulting in very narrow intercalations. Spiral cords with weakly convex or nearly flat tops. Suture distinctly incised. Lateral sinus with low to moderately steep angle; simple, shallow with faint inflection points, wide; adapical LS p. Basal sinus and aperture unknown. Internal sculpture consisting of about 16 discontinuous palatal and basal spiral lirae, separated by slightly wider interspaces.

Shell measurements and ratios. No complete specimen available; largest fragment (SL: 30.5 mm, MD: 9.2 mm) suggests maximum height of ~ 40 mm and ~ 10 mm diameter. AA: ~25°, PA: ~15–18°. Lateral sinus (n = 5): LS° = 13.4° (σ = 1.1°), LS p = 0.7 (σ = 0.1), LS d = 8.0 (σ = 1.7).

Discussion. This species is highly reminiscent of Viennella incisaeformis Csepreghy-Meznerics, 1956 and is commonly mixed with that species in museum lots. Nevertheless, V. incisaeformis differs from V. ignorata in its regular spiral sculpture and lower number of spiral cords, due to a lack of secondary spiral cords. The broad interspace between the two adapical spiral cords and the slight subsutural concavity characterize V. incisaeformis . The slightly imbricate whorl profile of V. ignorata , which results in a somewhat stocky appearance, does not occure in V. incisaeformis . In addition, the internal lirae of V. incisaeformis are more prominent and less numerous compared to V. ignorata . Finally, V. incisaeformis is found in offshore clays, whereas V. ignorata is mainly (though not exclusively) found in shallow water deposits with indication of seagrass.

Sieber (1960) identified this species from the middle Miocene of the Vienna Basin with the Italian Turritella (Haustator) laevissimus subrotundula Sacco, 1895 , which was adopted subsequently by Stürmer (1989) and Schultz (1998). Turritella laevissima was described by Mayer (1866: 174, pl. 3, fig. 4) from the Burdigalian of the Torino Hills in Italy. He described and illustrated a slender shell of high, flat sided whorls with faint sculpture and narrow suture. Later, Sacco (1895: 16, pl. 1, figs. 57a–57b) documented two additional specimens from the type region, which fully correspond to Mayer’s drawing. For specimens with slightly more convex whorls, Sacco (1895) introduced the variety name subrotundula ( Sacco 1895: 16, pl. 1, figs. 58a–58b). Viennella ignorata , however, differs from the Italian Turritella laevissima in its less slender profile, more incised suture and more convex whorls. Moreover, the position of the periphery is close to the abapical suture in V. ignorata but at mid-whorl in “T.” laevissima subrotundula. Finally, the delicate but distinct sculpture of V. ignorata differs from that of the nearly smooth “ T”. laevissima .

Paleoenvironment. The species occurs at localities indicating shallow neritic environments with seagrass (Gainfarn, Steinebrunn) and also at localities with middle to outer neritic assemblages (Bad Vöslau).

Distribution. Central Paratethys. Badenian: Vienna Basin: Steinebrunn, Gainfarn, Baden, Bad Vöslau ( Austria) ( Sieber 1960; herein); Pannonian Basin: Szob, Kismaros ( Hungary) ( Strausz 1966; Báldi & Kókay 1070).

Figures

FIGURE 6. Growth line traces of Turritellidae species based on own data; bold: type species of genera; black: Paratethyan species; asterisk: non-Paratethyan species (unknown basal sinuses are left blank).

FIGURE 20. A–B. Turritellinella subuliformis (Boettger, 1907), Lăpugiu de Sus (Romania, A1–A2. NHMW 2018/0181/0008. B1–B2. NHMW 2018/0181/0009. C1–C2. Turritellinella tricarinata (Brocchi, 1814), Adriatic Sea, NHMW 2018/0302/0001.

FIGURE 21. A–D. Viennella incisaeformis (Csepreghy-Meznerics, 1956). A. Holotype, Ipolydamásd (Hungary), M.61.4303. B. Baden (Austria), NHMW 2013/0078/0716. C. Baden (Austria), NHMW 2018/0223/0004. D1–D2. Bad Vöslau (Austria), NHMW 2018/0303/0001. E–I. Viennella ignorata new sp. E. Paratype, Bad Vöslau (Austria), NHMW 2018/0303/0003. F. Holotype, Steinebrunn (Austria), NHMW 1963/0528/0000. G. Paratype, Gainfarn (Austria), NHMW 2018/0272/0005. H. Para- type, Steinebrunn (Austria), NHMW 1963/0551/0000. I. Paratype, Steinebrunn (Austria), NHMW 1871/0010/0379.